For example, Non-Patent Document 1 discloses a communication system configured such that any two communication devices are taken from a large number of communication devices to make a plurality of pairs of communication devices, each pair capable of transmitting data in an asynchronous DS-CDMA (Direct-Sequence Code Division Multiple Access) system.
Non-Patent Document 2 discloses a communication system where a receiving device feeds back a hopping pattern to a transmitting device.
Non-Patent Document 3 discloses an initial value of the hopping pattern P.
[Non-Patent Document 1]: Asynchronous Decentralized DS-CDMA Using Feedback-Control Spreading Sequences for Time-Dispersive Channels, (Kazuki CHIBA, Masanori HAMAMURA and Shin'ichi TACHIKAWA, IEICE TRANS COMMUN, VOL. E91-μ, NO1. JANUARY 2008, PAPER, Special Section on Cognitive Radio and Spectrum Sharing Technology, The Institute of Electronics, Information and Communication Engineers)[Non-Patent Document 2]: Interactive constructions of optimum signature sequence sets in synchronous CDMA systems, (S. Ulukus et. al., IEEE Trans. Inform., Theory, vol. 47, no. 5, pp. 1989-1998, July 2001)[Non-Patent Document 3]: Address assignment for a time-frequency-coded spread-spectrum system (G. Einarson, Bell Syst. Tech. J., vol. 59, no. 7, pp. 1241-1255, September 1980)